CVE-2026-3787

UltraVNC Windows Service cryptbase.dll uncontrolled search path

HIGH
7
CVSS Score
Published: March 8, 2026 at 11:02 PM UTC
Updated: June 17, 2026 at 10:44 AM UTC
2 products affected across 2 vendorsUltraVNCUltraVNC

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Severity
HIGH7
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

A weakness has been identified in UltraVNC 1.6.4.0 on Windows. This affects an unknown function in the library cryptbase.dll of the component Windows Service. This manipulation causes uncontrolled search path. The attack requires local access. A high degree of complexity is needed for the attack. The exploitability is reported as difficult. The vendor was contacted early about this disclosure but did not respond in any way.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions
microsoft-windows (environment)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (4)

VDB EntryThird Party Advisory
Source: cverecord
https://vuldb.com/?id.349754
SignaturePermissions RequiredVDB Entry
Source: cverecord
https://vuldb.com/?ctiid.349754
Third Party AdvisoryVDB Entry
Source: cverecord
https://vuldb.com/?submit.767257

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7HIGHVulDB
Vector?

Quick Info

StatusANALYZED
CWE
CWE-427CWE-426

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